/// <summary>
/// Computes a memory layout for a given type descriptor.
/// </summary>
/// <param name="td">type descriptor to layout</param>
/// <param name="info">marshalling information</param>
/// <returns>memory layout</returns>
public static MemoryLayout Layout(TypeDescriptor td, IMarshalInfo info)
{
Type type = td.CILType;
ISerializer ser = SLVSerializable.TryGetSerializer(type);
if (ser != null)
{
object sample = td.GetSampleInstance();
return CreatePrimLayout(ser.Serialize(sample).Size, td, info);
}
if (ser == null && td.HasIntrinsicTypeOverride)
throw new InvalidOperationException("Type " + type.Name + " has intrinsic type override but no serializer");
if (type.IsEnum)
{
return new EnumMemoryLayout(td, info);
}
if (type.IsArray)
{
td.AssertStatic();
TypeDescriptor elemTd = td.Element0Type;
MemoryLayout elemLayout = Layout(elemTd, info);
ulong subStride = elemLayout.SizeInBits;
if (subStride == 0)
{
return new EmptyMemoryLayout(td)
{
Size = 0,
SizeInBits = 0
};
}
ulong[] strides = new ulong[type.GetArrayRank()];
ulong elemsPerWord = (ulong)info.WordSize / elemLayout.SizeInBits;
ulong wordsPerElem = elemLayout.Size;
if (elemsPerWord > 1)
{
if (info.UseArraySubWordAlignment)
{
if (info.UseArrayDimPow2Alignment)
{
elemsPerWord = MathExt.FloorPow2(elemsPerWord);
subStride = info.WordSize / elemsPerWord;
}
}
else
{
elemsPerWord = 1;
}
}
ulong dimSize = (ulong)(int)td.TypeParams.Last();
ulong dimWords;
if (elemsPerWord <= 1)
{
subStride = 0;
if (info.UseArrayDimPow2Alignment)
wordsPerElem = MathExt.CeilPow2(wordsPerElem);
dimWords = wordsPerElem * dimSize;
}
else
{
wordsPerElem = 0;
dimWords = (dimSize + elemsPerWord - 1) / elemsPerWord;
}
strides[strides.Length-1] = wordsPerElem;
for (int i = strides.Length-2; i >= 0; i--)
{
if (info.UseArrayDimPow2Alignment)
dimWords = MathExt.CeilPow2(dimWords);
strides[i] = dimWords;
dimSize = (ulong)(int)td.TypeParams[i];
dimWords *= dimSize;
}
return new ArrayMemoryLayout(td, info.WordSize, strides, subStride, (uint)elemsPerWord, (uint)wordsPerElem, elemLayout)
{
Size = dimWords,
SizeInBits = dimWords * info.WordSize
};
}
if (type.IsValueType && !type.IsPrimitive)
{
StructMemoryLayout ml = new StructMemoryLayout(td);
FieldInfo[] fields = type.GetFields(
BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
ulong offset = 0;
foreach (FieldInfo field in fields)
{
TypeDescriptor fieldTd = td.GetFieldType(field);
MemoryLayout fieldLayout = Layout(fieldTd, info);
FieldLocation fieldLoc = new FieldLocation(field, fieldLayout, offset);
ml.AddLocation(fieldLoc);
offset += fieldLayout.Size;
}
ml.Size = offset;
ml.SizeInBits = offset * info.WordSize;
return ml;
}
throw new InvalidOperationException("Unable to create data layout for type " + type.Name);
}